Most of the soils of New Zealand vineyards are derived from glacially produced sediments. The current ice age started about 2.5 million years ago. Of this period New Zealand glacial sediments cover the last 650,000 years.

The major cycles of this ice age, cold to warm to cold, have a length of about 105,000 years. As well there are numerous shorter span cycles, thus as the main cycle breaks from the cold spell there can be a number of colder and warmer periods as it heads down to the maximum part of the warm cycle. We are probably in the maximum part of the warm cycle now.

Because this cold warm cycle has been repeated again and again the same processes of sediment creation and deposition have been repeated. Thus many of the vineyard sites have a common origin and are composed of similar, glacially derived sediments though they can be of different ages.

Glaciers are very powerful erosional forces grinding away rock as they advance to produce an unsorted blend of boulders, lumps of rock, and crushed rock fragments of all sizes to particles as fine as flour. Retreating glaciers leave behind this load of unsorted rock debris, termed till. Deposits of till are normally eroded by streams from retreating glaciers but can be preserved if they are on the sides of a valley, are very recent, or are so large that streams have diverted around them. This is very apparent in the Cromwell Basin, Otago.

Streams emerge from the tongue of the glacier particularly during seasonal melting and large volumes of water, thick with sediment flow over a wide area. These form outwash fans and the many streams flowing across the fans meet to form a swift flowing river which is normally braided, meaning many streams criss-cross over the valley floor. Many of the New Zealand valley floors are quite wide and can be from three to twelve kilometres, being wider of course closer to the ocean outfall.

These streams rapidly work the rock fragments into the characteristic oval and round cobble shapes so common along New Zealand streams. As well previous deposits are eroded and there is a constant washing and grading of older river bed sediments.

Both the outwash fans and the river terraces, composed of cobble, sand and silt beds, are ideal for vines as they drain very easily.

A feature of the vineyard regions is the stepping of terrace levels from higher and older terraces abutting the valley slopes, to progressively lower and younger terraces close to the river. The dissection of previous terrace levels can happen in a number of ways.

The intensity of each glacial phase varies and a particularly cold phase with thicker ice will lead on melting to a swifter river. This can erode the previous terrace level particularly if the river can deepen the channel. Sea water levels will also have a role and if a lot more of the continental shelf is exposed this additional gradient will also allow the river to cut back upstream. Lastly New Zealand is a geologically unstable country thus it is likely that at times valleys and the terraces have been uplifted. This will alter the gradient of the river which may then cut down into the bedrock, creating a newer and lower terrace, stranding the older terraces.

Multiple terrace levels are very common in New Zealand wine regions and can be seen in the Cromwell basin, Marlborough and Martinborough. These terraces have proved to be very favourable for vineyards when they have good sunlight exposure and are drier than surrounding areas.

Glaciation is also associated with dry periods and cold winds and a feature of glaciated terrain is wind blown silt, termed loess that is frequently found capping the surface terrace sediments. This is common in Otago and in parts of Marlborough and possibly Martinborough. The term soil hardly seems to apply in some of the vineyard areas as the sediment base is very young, being post glacial at less than 10,000 years, and soil horizons in the conventional sense with an organically enriched top horizon are mostly absent.

Some elements do go into solution readily and in Otago nodules of calcrete (calcium carbonate) were found in recent scree slopes that looked like they had tumbled down very recently, an illustration that modification of sediments and the development of soil horizons can happen quickly.

Similar glacially derived ‘soil’ types are common in Argentine and Chile. Sediments in the parts of the Rhone Valley, particularly Chateau Neuf du Pape and more famously the left bank of Bordeaux also have a glacial origin although they show more sorting or grading by water as they are further from the glacial source.

The vineyard soils of Australia and New Zealand are startling different. While many Australian vineyards are on transported sediments like New Zealand these are mostly river sediments and are very fine grained.

In other areas the soil profiles can be well developed, particularly the lower horizons and it is not unusual to find many metres of deeply weathered rock before signs of fresh rock is found. It is quite possible that these deeply weathered zones are millions of years old. This author does though have the view that the near surface layers are likely to be recently formed as the chances for surface erosion are so high. Like New Zealand the top layer will also contain a much higher component of wind blown silt than is commonly recognised.

In this description we have only dealt with the common glacial origin of the vineyard soils. Other terroir influences such as sun light hours and temperature, rainfall, exposure of the vineyard to wind and sun, diurnal variations in temperature, influence of the prevailing weather pattern from the southern ocean and many other variables may be more important for grape quality and need to be woven into this base to form the overall terroir picture.

The regions to be discussed in detail are Central Otago, Marlborough and Martinborough.

Tuesday, 21st June, 2016

The Federation debate continued the rivalry between Sydney and Melbourne with the location of the new capital being of great importance. After reviewing many sites the Australia Capital Territory was selected in 1908 at a mid way point between the two cities and declared on 1st January, 1911. Canberra was named as the location in 1913 and Canberra Day is remembered on the 12th March.
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Wednesday, 29th July, 2015

Few wine commentators wish to understand the significance of the Murray Basin taking the view that the basin is no more than a maker of industrial wines. The average wine buyer cannot afford the wines they like to write about and to make price sensitive wines you need regions like the Murray Basin. After all over 60% of the country's wine comes from the Murray Basin while supplying the 30% packaged as casks.
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Wednesday, 29th July, 2015

To appreciate the wine story of the Murray Basin it helps to understand how the basin formed, or its geological evolution. Please note this long section has no bearing on wine flavours. Also it is a simplification and re-arrangement of the published information. Three issues are of special interest in considering how the Murray Basin evolved;
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Sunday, 12th January, 2014

The following six articles are based on a talk I gave to the Field Geologists Club of South Australia, on May 2nd 2013.

I took the opportunity to talk to this group to consolidate my thoughts which are captured in the general term 'terroir' which have been maturing since the late 1990s, a time when I wanted to understand the science behind the role of nature, as distinct from wine-making, in the flavours of wine.
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Wednesday, 28th March, 2012

The birthplace of Australian wines was naturally the Sydney basin. Urban pressure has swamped the vineyards of Sydney though a few lonely outposts survive, such as Camden Estate Wines at Camden where the first plantings date to 1820. Thus it was to be further north in the Hunter Valley that the early vineyards were to survive. more...

Monday, 6th February, 2012

In August, 2010, a geological map of the McLaren Vale wine region was published. This is the final version of a preliminary map from 2000. I love maps and to me both are works of art though the full blown 2010 version is a thing of beauty. This map shows in great detail the many geological formations from very young to old which underlie this famous vineyard region. more...

Thursday, 29th September, 2011

Quick Facts
The Eden Valley GI region adjoins the Barossa Valley to the east and is of a similar size.
This region is a hilly upland plateau divided in two by the valley of the North Para River which flows north.
This upland region is about 200 metres higher than the Barossa Valley and vineyards are planted at heights of 400 to 550 metres. more...

Sunday, 11th September, 2011

Should you be interested in creating a wine empire, The Daily Mail, 17th July, 2011, reports that the Estancia Punta del Agua; a one million acre estate, in San Juan province in western Argentine, is for sale. The estate lies about 150 kilometres NNE, of San Juan which has a wine history back to 1569. more...

Sunday, 1st May, 2011

When commenting about wine regions it's not a simple task to write about the geology and the origin of landscapes and soils. Consider this example of the confusion that one region has managed.

Heathcote, the Victorian region noted for fine shiraz makes great use of the districts red soils in selling and marketing. Some say the best vineyards are located on the red soils, and it's suggested, they produce the best wines. Here are nine recent comments. more...

Thursday, 7th April, 2011

Looking back over the last 40 years it is amazing the number of new wine regions that have developed across Australia and New Zealand. From farming land to vineyards and still pioneers are finding small sub-regions that are worth a shot. more...

Wednesday, 22nd December, 2010

For a dozen or so years now I have spent many happy days digging holes, chipping rocks, and studying the landscapes of a large number of Australian and New Zealand vineyard regions. The object is to try and understand what role things like soils, rocks, and the shape of the landscape, play in the role of creating wine flavours. This is an area French winemakers are very keen on and goes under the general topic of 'terroir'.
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Wednesday, 19th May, 2010

My studies have lead me to the conclusion that the chemistry of the soils and rocks in which the vine grows add little if anything to the taste of wine. Wine does not show a taste that can be related back to primary or secondary minerals in the soils and weathered rocks. The soils and rocks do though have an important bearing on how necessary nutrients are taken up by the vines and most specifically how the vine gains access to water. This does affect the taste in a major way. more...

Monday, 27th July, 2009

I have written a lot about the topic of 'terroir' and was recently asked by Max Marriot, landscape photographer and specialist writer, to offer some thoughts about geology, wine and the like. This was to help with an article he was commissioned to do for the New Zealand Grape Grower. more...

Wednesday, 10th June, 2009

I have spent many a happy day wandering the hills and vales pondering how the Barossa landscape formed. An area of great interest is Rocky Gully that runs down from the eastern edge of the Eden Valley into the Barossa Valley. This gully makes no sense to me as it seems to be much bigger than the tiny stream that drains it could possibly have created. more...

Wednesday, 1st April, 2009

The Chaytor family were early Marlborough settlers (1830-40?) and had grazing properties that spanned country from north of Blenheim at Spring Creek through to Picton. One of these properties, possibly 'Marshlands', near Spring Creek, is now part of the extensive vineyard, Shepherds Ridge, of 73 hectares. Alas I do not have firsthand experience of the Shepherds Ridge vineyard. Wine reviews have been very favourable with many wines scoring 90 plus.
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Saturday, 6th September, 2008

The concept of 'terroir' or a sense of place that it is said may be reflected in the taste of a wine is now embedded in the psyche of French wine makers and many disciples world-wide. It was not always so as there is little mention of this concept until the 1970's though it can be argued that it encapsulates the idea of single vineyards as represented for example by the 1855 Bordeaux left bank grading. more...

Sunday, 22nd June, 2008

If you believe what wine writers everywhere are telling us you would come to the conclusion that the very best wines are always site specific. By this they mean you must be able to see the vineyard which produced the grapes and coupled with this they may discuss how the wine expresses the terroir of the site. more...

Friday, 11th April, 2008

Currently a number of wine writers are emphasising that wines with a sense of place taste better, or those that express terroir have the true taste of wine. Indeed I gather they are saying that they can detect a wine with a sense of place from drinking it. more...

Wednesday, 3rd October, 2007

The idea that the site, the location and aspect, of the vineyard and its exposure to the elements of climate will affect the taste of the grapes and hence the wine seems so obvious as to be hardly worth debating. Any owner of a vineyard whether it is flat as a tack in the Australian Riverland or clinging to a slope in a cool climate region will tell you that part of the vineyard always produces superior fruit to the rest. The famous region of Burgundy has known for five hundred years that parts of its golden slope produce better wines than the rest. more...

Thursday, 18th September, 2006

An aspect of marketing is to tell the story about the product and to enhance the story it can be a good idea to weave in a myth, a mystery or some 'undefined' extra element. The idea is to create for the consumer an emotional bond with the product that goes beyond the mere utility of the product. more...

Tuesday, 4th July, 2006

It seems to make sense that the taste of a wine reflects where it is grown. After all Barossa wines do have different aromas and flavours to Tasmanian wines. The French use the term 'terroir' to describe the differences that refect the sense of place where the grapes are grown. more...

Friday, 14th October, 2005

Olivier Gergaud from the University of Reims and Victor Ginsburgh (pictured) of the Université Libre de Bruxelles deserved better than the couple of smart headlines they attracted when they presented a paper at the UK Royal Economic Society annual conference in Nottingham in March this year. The Sunday Observer declared "French bitter over wine study" and Decanter magazine on its website summarised that "Terroir plays no role". But apart from a reference or two on wine web sites that was the extent of the references that I found on Google for the paper Natural endowments, production technologies and the quality of wines in Bordeaux. Does terroir matter? Yet the Gergaud and Ginsburgh paper is one of the more significant contributions yet made to the debate about the comparative impact of terroir and wine making skills on the wine we drink. A look at the Observer's and Decanter's coverage of the story perhaps provides a clue to the overall paucity of the coverage. more...

Friday, 14th October, 2005

Any vineyard owner will tell you that certain areas of their vineyard make better tasting grapes than other areas. Why some areas of vineyards and vineyard districts deliver better grapes and hence better wine is the subject of terroir studies. The Europeans and particularly the French are very interested in this topic. They extend the meaning of the word which we can roughly say is the flavour effects that come from the vineyard location to include cultural ideas which unite man with the soil. more...

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